If you go to the
Scriptural texts, Christians were called upon to refute error. The apologists
in the early church were required to answer false charges against Christians.
In First Peter, you have the classic verse for apologetics - always be prepared
to give an answer for the reason of the hope that is within you, yet do it with
gentleness. That is an imperative in Greek, and it is not just applied to
pastors and theologians. It is for everybody. It is a command.

The
Church has always made a distinction between things that were most central and
really worth defending and everything else. Or, fundamental and non-fundamental
truths - the primary and the secondary. I am not going to go to the wall
against the guy down the street who has a wrong interpretation of what it means
to be baptized for the dead or that a woman is going to be saved by her
child-bearing. But if you are talking about something that has to do with the
plan of salvation or how a person is going to become righteous before a holy
God, if we love people enough we will fight for that truth.

How did
the Christians of the past practice apologetics?

In the Book of
Acts, where you find the earliest preaching of the Apostles, there was a
continuity between the preaching of the Gospel and the defense of the Gospel.
If, for example, they were dealing with the Gnostics, they proclaimed the
Gospel pointed out that Jesus Christ had come in the flesh, and simultaneously
pointed out that the position of the Gnostics was false. If you read or confess
what the Nicene Creed says about Jesus "God of God, Light of Life, very God of
very God, begotten, not made, being of one substance with the Father" - the
Church said these things because the Jehovah's Witnesses of their day were
taking the field. They taught that Jesus was God's finest Idea, and one day he
made himself a son. He was not eternal. The Church went on record with the
Nicene Creed to present truth and point out error.

It is not a part of
our culture to take the sort of style that our confessors did when they wrote
those early sixteenth century documents. They would say that we believe this,
this, and this, and therefore we condemn that, that, and that. In contemporary
American culture, as feminizes as it is, people do not view things - primarily
at the level of truth. But rather, are they nice? Speaking against error does
not sound nice.

The Bible says that a little leaven will leaven the
whole lump. What does that mean?

You cannot say that just because
there is a little leaven in a movement that it will always corrupt the whole
thing. We don't have the mind of God to say that. But if you examine
historically how this has gone, usually, given enough time, the leaven of
unbelief has a way of getting at the central things. In other words, the old
Lutherans would say, "What's this going to do to the doctrine of Christ's
death. What's it going to do to salvation by grace alone?" If it starts to eat
away at it, you've got deep trouble. In many ways, heresies, though they begin
way out on the edges, have a way of munching their way to the center.

Every professor has to think about this, because he might be teaching
something that is not in accord with truth, either knowingly or unknowingly.
And for certain, his students are going to take it further. Students have a way
of doing that. That is why there is a double standard of judgment for teachers.
In some ways, I am responsible for what my students teach. That is the way it
has gone throughout history.